Two-dimensional layered magnesium–cobalt hydroxide crochet structure for high rate and long stable supercapacitor application (original) (raw)
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Advanced Functional Materials, 2013
We aim to fabricate a ZnCo layered double hydroxide (LDH) nanostructure through facile one-pot hydrothermal synthesis. ZnCo LDH with interconnected hexagonal sheets having ultrathin thickness with voids are synthesized for the effective penetration of electrolytes to achieve superior electrochemical properties. The as-synthesized ZnCo LDH nanostructure is then subjected to structural, morphological, phase, and electrochemical studies. As an electrode for a supercapacitor, the ZnCo LDH has an areal capacitance of 1964 mFcm-2 at a 5 mVs-1 scan rate, an energy density of 0.22 mWhcm-2 , and an excellent cycling stability (112 %) after 2000 charge discharge cycles.
A Review of Cobalt-Based Metal Hydroxide Electrode for Applications in Supercapacitors
Advances in Materials Science and Engineering
Supercapacitors are the cutting-edge, high performing, and emerging energy storage devices in the future of energy storage technology. It delivers high energy and produces higher specific capacitances. This research study provides insights into supercapacitor materials and their potential applications by examining different battery technologies compared with supercapacitors’ advantages and disadvantages. Transition metal hydroxides (cobalt hydroxides) have been studied to develop electrodes for supercapacitors and their use in various fields of energy and conversion devices. Cobalt-based metal oxides and hydroxides provide high-capacitance electrodes for supercapacitors. Metal hydroxides combine high electrical conductivity and excellent stability over time. The metal oxides used to prepare the electrodes for supercapacitors are cobalt-based metal oxides and hydroxides. It is stronger than most of the other oxides and has tremendous electrical conductivity. Cobalt hydroxides are als...
Applied Clay Science, 2017
This paper describes the electrosynthesis and characterization in alkaline solutions of two layered double hydroxides (LDHs) containing Co as divalent cation and Al or Fe as trivalent one on Pt supports. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) experiments demonstrated a capacitive behaviour. LDHs containing Al 3+ or Fe 3+ displayed different responses, highlighting a key role of the trivalent metal. High specific capacitances calculated from charge-discharge experiments at a current density of 1 A g − 1 , were displayed by the two materials and resulted 854 and 869 F g − 1 for the Al or Fe containing LDH, respectively. The long-term cycling capability was also investigated giving satisfactory results. The presence of Fe improves the performance of the LDH as pseudocapacitor, especially to achieve better performances in terms of energy and power densities. In view of the development of low cost supercapacitors preliminary tests aimed to deposit Co based LDHs on a large area graphite substrate were also successfully carried out.
Atomic-level energy storage mechanism of cobalt hydroxide electrode for pseudocapacitors
Cobalt hydroxide is a promising electrode material for supercapacitors due to the high capacitance and long cyclability. However, the energy storage/conversion mechanism of cobalt hydroxide is still vague at the atomic level. Here we shed light on how cobalt hydroxide functions as a supercapacitor electrode at operando conditions. We find that the high specific capacitance and long cycling life of cobalt hydroxide involve a complete modification of the electrode morphology, which is usually believed to be unfavourable but in fact has little influence on the performance. The conversion during the charge/discharge process is free of any massive structural evolution, but with some tiny shuffling or adjustments of atom/ion species. The results not only unravel that the potential of supercapacitors could heavily rely on the underlying structural similarities of switching phases but also pave the way for future material design for supercapacitors, batteries and hybrid devices.
Scientific Reports, 2015
Hierarchical nanoarchitecture and porous structure can both provide advantages for improving the electrochemical performance in energy storage electrodes. Here we report a novel strategy to synthesize new electrode materials, hierarchical Co-based porous layered double hydroxide (PLDH) arrays derived via alkali etching from Co(OH) 2 @CoAl LDH nanoarrays. This structure not only has the benefits of hierarchical nanoarrays including short ion diffusion path and good charge transport, but also possesses a large contact surface area owing to its porous structure which lead to a high specific capacitance (23.75 F cm −2 or 1734 F g −1 at 5 mA cm −2) and excellent cycling performance (over 85% after 5000 cycles). The enhanced electrode material is a promising candidate for supercapacitors in future application.
Recent Developments in Supercapacitor Electrodes: A Mini Review
ChemEngineering
The use of nonrenewable fossil fuels for energy has increased in recent decades, posing a serious threat to human life. As a result, it is critical to build environmentally friendly and low-cost reliable and renewable energy storage solutions. The supercapacitor is a future energy device because of its higher power density and outstanding cyclic stability with a quick charge and discharge process. Supercapacitors, on the other hand, have a lower energy density than regular batteries. It is well known that the electrochemical characteristic of supercapacitors is strongly dependent on electrode materials. The current review highlights advance in the TMOs for supercapacitor electrodes. In addition, the newly discovered hybrid/pseudo-supercapacitors have been discussed. Metal oxides that are employed as electrode materials are the focus of this study. The discovery of nanostructured electrode materials continues to be a major focus of supercapacitor research. To create high-performance ...
Electrode Materials for Supercapacitors: A Review of Recent Advances
Catalysts
The advanced electrochemical properties, such as high energy density, fast charge–discharge rates, excellent cyclic stability, and specific capacitance, make supercapacitor a fascinating electronic device. During recent decades, a significant amount of research has been dedicated to enhancing the electrochemical performance of the supercapacitors through the development of novel electrode materials. In addition to highlighting the charge storage mechanism of the three main categories of supercapacitors, including the electric double-layer capacitors (EDLCs), pseudocapacitors, and the hybrid supercapacitors, this review describes the insights of the recent electrode materials (including, carbon-based materials, metal oxide/hydroxide-based materials, and conducting polymer-based materials, 2D materials). The nanocomposites offer larger SSA, shorter ion/electron diffusion paths, thus improving the specific capacitance of supercapacitors (SCs). Besides, the incorporation of the redox-ac...
As an alternative to rechargeable batteries, pseudocapacitors feature high power density, fast charge – discharge kinetics and long cycling stability for energy storage. Compositional modification by redox site enrichment is an effective strategy to increase the energy density and enhance the Faradaic reactions of pseudocapacitive materials. Transition metal layered double hydroxides (TM-LDHs) feature a layered structure and modifiable transition metal content for pseudocapacitive energy storage. In an earlier report, we demonstrated that for NiAl-LDH materials increase of Ni/Al ratio leads to expanded van der Waals (vdW) gap enabling fast charge– discharge kinetics, degraded crystallinity, and retention of 2D layered structure featuring high cycling stability. Here, coupling near-room temperature acid solution calorimetry, in situ X-ray diffraction (XRD), and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), we find that as the Ni/Al ratio increases, bot...